1. Field of the Invention
This invention relates to a thermodevelopable photographic material, and especially to a thermodevelopable photographic material containing a high silverion conducting material having an ion conductivity at 25.degree.C of at least 1 .times. 10.sup.-.sup.3 (.OMEGA.cm).sup.-.sup.1.
2. Description of the Prior Art
The photographic materials which have previously been utilized include those bases on silver halides. When exposed to a light image for a long time, some of them undergo visible darkening. Recently, U.S. Pat. Nos. Re 26,719 and 3,457,075, for example, disclose a thermodevelopable photographic material consisting of a sheet and coatings of an organic silver salt, a catalytic amount of a light-reducible silver halide, and a weak reducing agent. According to the techniques disclosed in these prior art references, when the photographic material is exposed, no visible image is formed, but when the exposed photographic material is heated at a suitable high temperature for a short period of time, a permanent visible image is formed in the exposed area.